Plot hole: It doesn't make much sense that Marie had to ask Walt and Skyler to pay Hank's medical bills. They both make good money! Hank is a DEA agent and she is some kind of medical professional. There is no reason in the world that this couple cannot afford this. Same thing with Walt.
Suggested correction: Their insurance doesn't cover the bills; without that, bills can stack up quickly. You need a lot higher salary than a DEA agent to cover it, even if he got as high as 120,000 USD a year. Marie can't work as she is taking care of her husband.
Other mistake: In a 2-year time period, why is it always the same time of year? When was Christmas? Or Halloween? Or summer when it gets up to 110 degrees in New Mexico? They are always dressed in long sleeves and beanies.
Continuity mistake: When the black and white intro of the plane crash plays, it shows Walt's truck completely destroyed, with every single window busted into pieces as if a meteor hit it. But yet he drives it after the plane crash, and only the windshield is cracked.
